Firefight,
I'll give you my two cents and I'll give it to you straight - by playing devil's advocate. From what you have written, you are 24 who is only now 'thinking' about seriously starting training - whether it be military or commercial. In terms of military flight training, I'm sure the selection process and the amount of people that go for it is even more difficult and numerous than the commercial side. And you will have to answer some very difficult questions.
Unfortunately getting "bad advice" is not going to tug at the hearts of the selction panel at Cranwel. What have you been doing since you left A-Levels at 18/19? Have you had a stable job - a career perphaps? Or have you been going from job-to-job for the past 6 years "finding" yourself and have only now realised (after watching a repeat of Top Gun) that it could be pretty cool - which it would obviously.
Getting a career in the Navy (don't you need to provide 8 years of service?) is absolutely no guarantee that you will transfer to pilot training. It just does not work like that. So you could be 32 before you start commercial training which could take a couple of years. But then again, if a weapons system officer appeals to you, then go for it. It's a job isnt it?
I hope I don't sound too negative here - I'm just playing the advocate because you will have difficult questions to answer.
I must say that from your post, I don't think beong a commercial pilot is really in your heart. Those who really really want to be a commercial pilot would not enter the military as a weapons-officer simply due to the time you have to spend in the military - naturally going in as a pilot is completely different.
I think you need to think a little harder as to what your ambition is. If it is a Navy pilot (as you can't be a RAF pilot) then go for the selection. What have you got to lose. But don't go in as a non-flying officer because I really can not see how you are persuing the pilot ambition.
If it is to be a commercial pilot, then stay in your job (providing you have one) and get your PPL done. Continue with the modular route and hope for the best for 2011/2012. At this point, I'll refer you to a Mr WWW, our resident soothsayer, who can give you an idea of the market around that time.